Thread: Would like some feedback on Pistons...

Hey guys! Is anyone here running the ZZP Federal Mogul hypereutectic pistons??? I know the JE would be better but they are a bit pricey for me at the moment.. Wanted to know if anyone is using the FMs and what they think of them.. Thanks!

I believe the FM's are considered OEM replacements. While I'm not running them specifically, they'd likely be a good stock quality replacement.

Originally Posted by BillBoost37

I believe the FM's are considered OEM replacements. While I'm not running them specifically, they'd likely be a good stock quality replacement.

:-/ Hummm... so they are not exactly something I want if I am planning on running a lot of boost through my motor... I wonder that kind of HP humbers they can support without going kamakazi...

Well.. most guys run stock pistons for a long time w/o issues. Guys like Todd Allen from Intense had a stock bottom end with around 460hp w/o issues. Killing pistons is more about the tune than it is about the amount of boost.

IIRC Darkhorizon is pushing some healthy amounts of turbo boostage through a stock bottom. (At least I think he's running a stocker). But then turbo boost is typically cooler in it's charge than SC boost.

Right. My buddy had an Ion Redline and he melted some forged units because he bombed on his tune... I just figured I would ask and see what they can do... Lower price tag helps a bit too. :-)

So, since i am building on a budget as it were, i can reuse my L67 stock pistons, but upgrade to the L32 rods and I should be in good shape for a while??? I am not looking for like 1000hp or anything... I think ill be pretty happy around 500 tops. Looking more for tq than hp actually. lol

Scratch that. Took my motor apart last night and two of the stock L67 pistons have parts of the skirt missing... No reusing those. :-P

I thought the L36 and L67 rods were the same and the L32 and L26 rods were also the same. The rods I have appear to be powered metal, but the pistons are NA. Is there a way to tell the difference between L32 and L26 rods. Mine don't have the cast iron line on the sides. Also, so both NA pistons handle less power than the SC pistons even with a correct tune and cooling?

Pick up a L32 block and don't skimp out on a tune, buy an aeroforce, wideband and save yourself an engine.

I would of bought a L32, but the cheapest in this area was $1200. They're a rare engine around here. Imports though are everywhere. This is before I knew about car-part.com.

I have 2 engines, 1 from the 98 Regal and 1 from the 98 GTP. The Regal is all original with an L67. The GTP has what looks like a Gen II junkyard block, but was rebuilt. It was supposed to be a new Gen III block from GM when I bought the GTP, but didn't notice until I pulled the engine, I'm not to happy with the previous owner. I'm currently building the engine for the Regal, the GTP will come later. I took the pistons from both engines to my machinist to have them checked. He noticed the dish of the pistons from the GTP wasn't as deep as the pistons from the Regal. One of the pistons from the GTP was chipped exposing the top ring. The Rods from the pistons on the GTP aren't the cast steel ones so I wanted to use them as I've heard of their better strength. The cast iron rods from the Regal can't be reused as one of them spun a bearing.

The engine that was in the GTP was running, but after having a transmission that was supposed to have a warranty fail and other things, I didn't trust the previous owner so I pulled the heads to check things out. Three of the cylinders have scores in them and one of the pistons was chipped. There were no signs of that chip falling off in the cylinder so it appears he actually assembled the engine like this.

My plans are to use the block from the Regal which has already been checked for crank and cam line, decked, and honed by my machinist. I bought some 2007 L32 heads, had him clean and pressure test them, I port and polished, and then took them back to my machinist for a valve job, milled the heads, and checked the valve guides. I was trying to determine which pistons to use before and I received different opinions. I was thinking of using the 9.4 ratio because 2 of my older friends (one of them is 60) and my machinist who's 61 who've built a number of engines recommended them, because you can only go so small of a pulley and then you run out of boost. Go with higher compression and create less heat. My machinist has a Grand National with 11 to 1 compression, it of course is turbo though. But if the 9.4 pistons are weaker than the SC pistons, then guess that scratches that idea.

Sorry for the long winded story, but I don't want to miss any details.

The GTP's rod's aren't cast iron (no cast lines) and they look a little thicker than the cast iron ones on the L67. I assume the L36 rods would also have been cast iron so it looks like it was rebuilt since it has Series II not Series III stamped on the block. Also the Crank looks like it has low miles. Good rods, I assume mean L32 rods? So I take it there are 4 different types of rods instead of just 2 (Series II and Series III)? The L67 pistons I have, have some wear on the skirts and have 205k miles on them but they've never seen mods more than a short air intake, 180 stat and a custom PCM tune. So I was going to use them and the what appears to be powder metal rods from the GTP and get some L26 pistons since one of the ones in the GTP was chipped and who know's the condition of the other 5. The other choice was use the L67 pistons, buy used pistons, or buy new L67 or L32 pistons (I hope I wouldn't have to spend that $300 something). I have a little too much time and money into this to get another engine.

That doesn't make sense it would have a series 2 stamp on the side of a series 3 engine. Wouldn't be the first time I heard GM do something like this though. How would you know this without seeing the engine pulled from an untouched 04+ Grand Prix, lol.

So then L67 pistons it sounds like then, heard the L32 pistons have a coating on the skirts and the L32 rods are supposed to be stronger because of the powder metallurgy. How much power were they making or what were the people doing when they broke the L32 rods? I have all the bearings, rings, etc already so there is a bit invested. I agree, putting money after bad is a bad idea, but I only have rods, pistons and cam to decide. My friend who used to be a machinist till he got hurt is helping me with the build. My machinist who did the block and head work has grown to like me and has cut me some really good breaks on price. He's been in a few magazines, one of the articles was hooked on Meth Super Chevy.

Thanks for your help

Figured they used the same casting. I've heard of alot of failures with those aftermarket pistons and I'd rather stay away from their $1000 price tag as I'm sure most would. I don't like the hesitation of a turbo, I want the instant power. My Malibu isn't turbo but it has about the same hesitation and I hate it. When I build the GTP, I might go turbo though cause I'll be looking for top power. This car will have a M112 of sorts once the motor is running and broke in.